Adding observer functionality to UINetworkQualityService

chrome/browser/net/nqe/ui_network_quality_estimator_service.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_NET_NQE_UI_NETWORK_QUALITY_ESTIMATOR_SERVICE_H_
 #define CHROME_BROWSER_NET_NQE_UI_NETWORK_QUALITY_ESTIMATOR_SERVICE_H_
 
 #include <map>
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "base/observer_list.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "net/nqe/cached_network_quality.h"
 #include "net/nqe/effective_connection_type.h"
 #include "net/nqe/network_id.h"
 #include "net/nqe/network_quality_estimator.h"
 
 class PrefRegistrySimple;
 class Profile;
 
 namespace net {
 class NetworkQualitiesPrefsManager;
 }
 
 // UI service to determine the current EffectiveConnectionType.
 class UINetworkQualityEstimatorService
     : public KeyedService,
       public net::NetworkQualityEstimator::NetworkQualityProvider {
  public:
   explicit UINetworkQualityEstimatorService(Profile* profile);
   ~UINetworkQualityEstimatorService() override;
 
+  // NetworkQualityProvider implementation:
+  // Must be called on the UI thread.
+  net::EffectiveConnectionType GetEffectiveConnectionType() const override;
+  // Must be called on the UI thread. |observer| will be notified on the UI
+  // thread.
+  void AddEffectiveConnectionTypeObserver(
+      net::NetworkQualityEstimator::EffectiveConnectionTypeObserver* observer)
+      override;
+  // Must be called on the UI thread.
+  void RemoveEffectiveConnectionTypeObserver(
+      net::NetworkQualityEstimator::EffectiveConnectionTypeObserver* observer)
+      override;
+
   // Registers the profile-specific network quality estimator prefs.
   static void RegisterProfilePrefs(PrefRegistrySimple* registry);
 
-  // The current EffectiveConnectionType.
-  net::EffectiveConnectionType GetEffectiveConnectionType() const override;
-
   // Tests can manually set EffectiveConnectionType, but browser tests should
   // expect that the EffectiveConnectionType could change.
   void SetEffectiveConnectionTypeForTesting(net::EffectiveConnectionType type);
 
   // Reads the prefs from the disk, parses them into a map of NetworkIDs and
   // CachedNetworkQualities, and returns the map.
   std::map<net::nqe::internal::NetworkID,
            net::nqe::internal::CachedNetworkQuality>
   ForceReadPrefsForTesting() const;
 
  private:
   class IONetworkQualityObserver;
 
   // KeyedService implementation:
   void Shutdown() override;
 
   // Called when the EffectiveConnectionType has updated to |type|.
   // NetworkQualityEstimator::EffectiveConnectionType is an estimate of the
   // quality of the network that may differ from the actual network type
   // reported by NetworkchangeNotifier::GetConnectionType.
   void EffectiveConnectionTypeChanged(net::EffectiveConnectionType type);
 
   // The current EffectiveConnectionType.
   net::EffectiveConnectionType type_;
 
   // IO thread based observer that is owned by this service. Created on the UI
   // thread, but used and deleted on the IO thread.
   std::unique_ptr<IONetworkQualityObserver> io_observer_;
 
+  // Observer list for changes in effective connection type.
+  base::ObserverList<
+      net::NetworkQualityEstimator::EffectiveConnectionTypeObserver>
+      effective_connection_type_observer_list_;
+
   // Prefs manager that is owned by this service. Created on the UI thread, but
   // used and deleted on the IO thread.
   std::unique_ptr<net::NetworkQualitiesPrefsManager> prefs_manager_;
 
   base::WeakPtrFactory<UINetworkQualityEstimatorService> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UINetworkQualityEstimatorService);
 };
 
 #endif  // CHROME_BROWSER_NET_NQE_UI_NETWORK_QUALITY_ESTIMATOR_SERVICE_H_